Intelligence Quotient IQ stands for intelligence quotient. The score describes a person’s intelligence level compared to other people. The average IQ is by definition 100; scores above 100 indicate a higher than average IQ and scores below 100 indicate a lower that average IQ. Most scores do not go much below 50 or above 150.
Originally, an IQ score was used to detect persons of lower intelligence, and to detect children of lower intelligence in order to place them in special education programs. The first IQ tests were designed to compare a child's intelligence to what his or her intelligence "should be" as compared to the child's age.
Not only do we look at the intelligence levels of children, today we compare an adult's objective results to the objective results of other adults. The IQ score is determined by how intelligent each test taker is compared to all other test takers, instead of comparing test takers to an arbitrary age related standard.
Standford-Binet The Stanford-Binet intelligence test used a single number, known as the intelligence quotient (or IQ), to represent an individual's score on the test. This score was calculated by dividing the test taker's mental age by their chronological age, and then multiplying this number by 100. For example, a child with a mental age of 12 and a chronological age of 10 would have an IQ of 120 (12 /10 x 100).
Process of Standardization The standardization process involves administering the test to a representative sample of the entire population that will eventually take the test. Each test taker completes the test under the same conditions as all other participants in the sample group. This process allows the establishment of norms, or standards, by which individual scores can be compared.
Intelligence test scores typically follow what is known as a normal distribution, a bell-shaped curve in which the majority of scores lie near or around the average score. As you look further toward the extreme ends of the distribution, scores tend to become less common.
IQ Score Scale
Intelligence Interval
Cognitive Designation
40 - 54
Severely challenged (Less than 1% of test takers)
55 - 69
Challenged (2.3% of test takers)
70 - 84
Below average
85 - 114
Average (68% of test takers)
115 - 129
Above average
130 - 144
Gifted (2.3% of test takers)
145 - 159
Genius (Less than 1% of test takers)
160 - 175
Extraordinary genius
IQ Expressed as Percentiles The percentile refers to the number of other test takers’ scores that an individual’s score equals or exceeds. If a child answered 25 questions and did better than 50% of the children taking the test he would score at the 50th percentile. However, if he answered 40 questions on the 50 item test and everyone else answered more than he did, he would fall at a very low percentile — even though he answered 80% of the questions correctly.
IQ
Percentile
65
01
70
02
75
05
80
09
85
16
90
25
95
37
100
50
105
63
110
75
115
84
120
91
125
95
130
98
135
99
What is Your Occupation According to Your IQ Score? The IQ score gives a good indication of the occupational group that a person will end up in, though not of course the specific occupation. Glen Wilson and Diana Grylls outline occupations typical of various IQ levels in their book, Know Your Child’s IQ,
140
Top Civil Servants; Professors and Research Scientists.
130
Physicians and Surgeons; Lawyers; Engineers (Civil and Mechanical)
120
School Teachers; Pharmacists; Accountants; Nurses; Stenographers; Managers.
IQ stands for intelligence quotient. The score describes a person’s intelligence level compared to other people. The average IQ is by definition 100; scores above 100 indicate a higher than average IQ and scores below 100 indicate a lower that average IQ. Most scores do not go much below 50 or above 150.
Originally, an IQ score was used to detect persons of lower intelligence, and to detect children of lower intelligence in order to place them in special education programs. The first IQ tests were designed to compare a child's intelligence to what his or her intelligence "should be" as compared to the child's age.
Not only do we look at the intelligence levels of children, today we compare an adult's objective results to the objective results of other adults. The IQ score is determined by how intelligent each test taker is compared to all other test takers, instead of comparing test takers to an arbitrary age related standard.
Standford-Binet
The Stanford-Binet intelligence test used a single number, known as the intelligence quotient (or IQ), to represent an individual's score on the test. This score was calculated by dividing the test taker's mental age by their chronological age, and then multiplying this number by 100. For example, a child with a mental age of 12 and a chronological age of 10 would have an IQ of 120 (12 /10 x 100).
Process of Standardization
The standardization process involves administering the test to a representative sample of the entire population that will eventually take the test. Each test taker completes the test under the same conditions as all other participants in the sample group. This process allows the establishment of norms, or standards, by which individual scores can be compared.
Intelligence test scores typically follow what is known as a normal distribution, a bell-shaped curve in which the majority of scores lie near or around the average score. As you look further toward the extreme ends of the distribution, scores tend to become less common.
IQ Score Scale
IQ Expressed as Percentiles
The percentile refers to the number of other test takers’ scores that an individual’s score equals or exceeds. If a child answered 25 questions and did better than 50% of the children taking the test he would score at the 50th percentile. However, if he answered 40 questions on the 50 item test and everyone else answered more than he did, he would fall at a very low percentile — even though he answered 80% of the questions correctly.
What is Your Occupation According to Your IQ Score?
The IQ score gives a good indication of the occupational group that a person will end up in, though not of course the specific occupation. Glen Wilson and Diana Grylls outline occupations typical of various IQ levels in their book, Know Your Child’s IQ,
References
http://psychology.about.com/od/psychologicaltesting/f/IQ-test-scores.ht
http://www.iqtest.com/faq.html#chart
http://www.audiblox.com/iq_scores.htm
http://www.iqtest.com/whatisaniqscore.html